Michael D. Coe

“Briefly, the Long Count consists of a tabulation of days elapsed since the supposed inception of the calendar, the total being expressed as so many cycles of differing magnitudes. The largest of these cycles is the baktun, containing 144,000 days; next, the katun, 7,200 days; then the tun, with 360 days; the uinal, with 20; and the smallest of all, always at the bottom of the column, the kin of one day. Each of these in the days of Maya ascendancy was shown with its own hieroglyph, while to its left stood the coefficient by which it was to be multiplied.”
― Michael D. Coe, America's First Civilization